Effect of different air-abrasion particles on metal-ceramic bond strength

Abstract

Background/purpose: Chipping and delaminating of veneering ceramics are critical problems in the fabrication of metal-ceramic restorations. The purpose of this study was to evaluate the effect of different air-abrasion particles on the shear bond strength of a ceramic to nickel-chromium (Ni-Cr) and cobalt-chromium (Co-Cr) alloys. Materials and methods: Forty square specimens (10 mm  10 mm  1.5 mm) were cast for each Ni-Cr and Co-Cr alloys. Specimens were divided into four groups for the air-abrasion procedures: 50-mm aluminum oxid particles (Al 2 O 3 ), 110-mm Al 2 O 3 particles, 30e50-mm synthetic diamond particles, and 60e80-mm cubic boron nitride particles. After the airabrasion procedures, specimens received ceramic veneering. The shear bond strength was determined at a crosshead speed of 1 mm/min. Data were statistically analyzed by a 2-way analysis of variance with post-hoc Tukey's test (a Z 0.05). Effects of the air-abrasion particles on each alloy were examined with a scanning electron microscope. Results: The highest bond strengths were obtained with application of air abrasion with 110-mm Al 2 O 3 particles and the lowest bond strengths were obtained with 50-mm Al 2 O 3 particles (P < 0.05).Conclusions: None of the tested alternative air-abrasion particles provided superior bond strengths compared with 110-mm Al 2 O 3 particles.

Evaluation of ceramic flexural strength of a cobalt-chromium alloy subjected to airborne particle abrasion and tungsten inert gas welding

“…This bond depends directly on the formation of an oxide layer on the surface of the metal before firing the ceramic [4][5][6] . The control of this layer can be facilitated by APA using Al 2 O 3 , which also increases the area and the degree of wettability of the metal framework for the application of the ceramic 8,9 .…”

“…Reports have claimed, however, that this process may compromise the marginal integrity of the metal, and that damage is directly proportional to the size of the Al 2 O 3 particle [23][24][25] . In a study comparing metal-ceramic adhesion in Co-Cr and Ni-Cr alloys, there was a better bond strength in specimens that used Al 2 O 3 particles 110 μm in size 8 .…”

“…There are three possibilities of retention, including Van der Waals forces, micromechanical retention and chemical bonding, which is the main factor, and is characterized by the exchange of oxides between the metal and the oxidizable elements of ceramics [4][5][6] . Several surface treatments have been studied, such as airborne particle abrasion (APA) with aluminum oxide (Al 2 O 3 ) particles, which is a commonly used method for providing mechanical retention, resulting in the formation of an oxide layer that facilitates adhesion of the porcelain and increases the metal surface energy [7][8][9][10] . However, the size of the particles used in this process varies.…”

Interfacial shear bond strength between different base metal alloys and five low fusing feldspathic ceramic systems

“…Külünk et al 21) used 50 and 110 µ alumina particles to determine the effect of alumina particle size on metal-ceramic bond strength and concluded that higher bond strength values were obtained with 110 µ alumina particles. On the other hand, the difference of chemical composition and stiffness between Co-Cr and Ni-Cr alloys may also affect the surface roughness of tested metal surfaces after a standard sandblasting procedure.…”

“…Although not completely defined, they claimed that the adhesion between ceramic and metal depends on suitable oxidation of the metal and interdiffusion of ions between metal and ceramic. Additionally, Külünk et al 21) reported that the bond strength between ceramic and casting alloy is determined by the strength of chemical bonds, mechanical interlocking, the type and concentration of defects at the interface, wetting properties, and the degree of compressive stress in the ceramic layer due to differences in the coefficients of thermal expansion between the metal and ceramic.…”